Having noticed it was Pi day before Google alerted me to the fact, I'm feeling pretty dorky. Following some links I found the current record holder for the most digits of pi computed. Seeing his algorithm is recursive I thought "Hey I could write that in F# with bigint." So here I am on Pi day computing pi.

There is no square root method built in so I had to make my own. It takes about 30s on my i7 to compute the first 100,000 digits. I confirmed the results against the record holders data.